Water-laid felt, leather fiber



Patented Feb. 10, 1931 UNITED STATES PATENT OFFICE HENRY PHILIP SHOIPNECK, OE DORCHESTER, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIIIGNMEINTS, TO ARDEN BOX TOE- COMPANY, OF WATER'I'OWN, MASSACHUSETTS, A

CORPORATION OF MASSACHUSETTS.

WATER-LAID FELT, LEATHER FIBER No Drawing.

In my prior Patent No. 1,57 4,126, granted February 23,, 1926, I disclosed a water-laid felt consisting of a fibrous mass and relatively longer Vegetable fibersdistrib-uted throughout the mass in felted relation therewith and capable of being impregnated with a thermoplastic binder.

According to my present invention, I substitute for the long vegetable fibers of my prior patent, leather fibers, which I find lend themselvespeculiarly to the felting action, interlacing and interweaving with the fibrous mass in such a manner as 'to afford a very strong felt. a

I obtain the leather from usual sources, and preferably shred or otherwise disintegrate it in any suitable machine, after which the shreds are mixed with a fibrous mass such as described in my said prior patent, and the mass run on a cylinder felting machine. The resulting felt may then be impregnated with any suitable binder or thermoplastic compound.

The shredded leather has a good felting action and results in a felt which is very strong and quite absorbent, a satisfactory mix felt\"consisting of approximately 30% leather shreds and 70% rag or other short fibered stock. 4

In order to reduce somewhatthe density of the leather stock and make'it more absorbent, I may replace a small portion thereof with long vegetable fibers. This makes the felt somewhat more porous so that it will more readily absorb the waterproofing subtance, a. characteristic mix consisting of approximately 60% short fibered stock, 30%

leather, and 10% long vegetable fibers. This same result may, however, be accomplished, if desired, by adding a small percentage say about 5%, of some softening agent, such as sodium bichromate, soda ash, or the-like. Under some circumstances, it may be advisable to replace some of the short fibered stock with a mineral fiber, such as asbestos, which greatly aids the forming of the resulting felt, a characteristic mix consisting of approximatey 60% short fibered stock, 30% leather, and 10% asbestos. I

By using short-fibered stock and long- Application filed June 29,

fibered leather stock in the. proportions hereinbefore given, it is possible to produce a' Well-felted product of uniform texture and at thesame time possessing high porosity, strength, and tear resistance. Such a product serves as an excellent base or foundation for impregnation with a thermoplastic binder in the production of box toe material such as hereinafter claimed. Because of the absence of sizing or waterproofing materials in the felt, the porosity of the felt is maintained at a maximum consistent with the use of the various fibers and fiber proportions hereinbefore' given, as a result of which the felt lends itself to ready and uniform impregnation by immersion in baths of liquefied thermoplastic compounds.

Various midifications in the proportions and materials of my invention may obviously be resorted to if within the limits of the appended claims.

' What I therefore claim and desire to secure fibers and asbestos distributed therethrough in felted relation therewith, and impregnated with a thermoplastic hinder, the proportions of the mix being substantially as follows:

short fibered base 60%,'long leather fibers 30%-and asbestos fibers 10%.

3. A water-laid felt consisting only of a short fibered base of rag stock, and much longer leather fibers and asbestos distributed throughout the mass in felted relation therewith, the proportions of the mix beingsubstantially as follows: short fibered base 60%, long leather fibers 30% andasbestos fibers 4. A water-laid felt consisting only. of a short fibered base and much longer leather, fibers and. asbestos uniformly distributed therethrough, the proportions of the mix be,- ing substantially as follows: short fibered base 60%, long leather fibers 30% and asbestos fibers 10%.

In testimony whereof I aflix my signature.

HENRY PHILIP SHOPNECK. 

